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1.
Sci Rep ; 14(1): 6643, 2024 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-38503767

RESUMO

The utilization of kidneys from donors with acute kidney injury (AKI) is often limited by unpredictable post-transplantation outcomes. The aim of our study was to identify protein mediators implicated in either recovery or failure of these organs. Forty kidney biopsies from donors with (20) and without AKI (20) were selected and then subdivided according to the post-transplant outcome defined as a threshold of 45 ml/min for the eGFR at 1 year from transplantation. Tissue homogenates were analysed by western blot to assess how the levels of 17 pre-selected proteins varied across the four groups. Samples from AKI kidneys with a poor outcome showed a fourfold increase in the levels of PPARg and twofold reduction of STAT1 compared to the other groups (p < 0.05). On the contrary, antioxidant enzymes including TRX1 and PRX3 were increased in the AKI kidneys with a good outcome (p < 0.05). An opposite trend was observed for the detoxifying enzyme GSTp which was significantly increased in the AKI group with poor versus good outcome (p < 0.05). The importance of lipid metabolism (PPARg) and inflammatory signals (STAT1) in the function recovery of these kidneys hints to the therapeutical targeting of the involved pathways in the setting of organ reconditioning.


Assuntos
Injúria Renal Aguda , Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , PPAR gama , Sobrevivência de Enxerto , Doadores de Tecidos , Rim/patologia , Injúria Renal Aguda/patologia , Biópsia , Estudos Retrospectivos
2.
Rev Med Virol ; 34(1): e2492, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37989714

RESUMO

Usage of self-screening tests has become increasingly relevant in public health perspective for early detection of SARS-CoV-2 infection in the transitioning era of the COVID-19 pandemic into an endemic. This study was designed to compare the diagnostic accuracy of self-conducted and health professional-conducted SARS-CoV-2 rapid antigen tests (Ag-RDTs) and whether the sample was taken from anterior nasal or nasal mid-turbinate. Eligible comparative Ag-RDTs accuracy studies were retrieved from electronic databases systematically, in accordance with PRISMA. Selected studies were assessed for risk of bias using QUADAS-2 and QUADAS-C. In total, we selected five out of 1952 studies retrieved using the keywords. The overall sensitivity for the self-collected nasal swab method and healthcare worker-collected nasopharyngeal swab method was 79% (95% CI 68-87; I2  = 62%) and 83% (95% CI 75-89; I2  = 32%), respectively, which was not statistically different (p = 0.499). Nasal mid-turbinate swabs have a significantly higher sensitivity compared to anterior nasal swabs (p < 0.01). Both sampling methods represent high and comparable specificity values of 98% (95% CI 97-99; I2  = 0%) and 99% (95% CI 98-99; I2  = 0%). Positive predictive value (range 90%-99%) and negative predictive value (range 87%-98%) were equivalent for both methods. Our findings indicated the accuracy of self-collected Ag-RDT on nasal swabs was comparable to those performed by healthcare worker-collected on nasopharyngeal swabs. Self-collected Ag-RDT could be considered as a transmission prevention method in the transition of COVID-19 pandemic.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , Pandemias , Antígenos Virais , Pessoal de Saúde
3.
Ann Surg ; 278(5): 676-682, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37503631

RESUMO

OBJECTIVE: To provide mechanistic insight into key biological alterations in donation after circulatory death kidneys during continuous pefusion we performed mass spectrometry profiling of perfusate samples collected during a phase 3 randomized double-blind paired clinical trial of hypothermic machine perfusion with and without oxygen (COMPARE). BACKGROUND: Despite the clinical benefits of novel perfusion technologies aiming to better preserve donor organs, biological processes that may be altered during perfusion have remained largely unexplored. The collection of serial perfusate samples during the COMPARE clinical trial provided a unique resource to study perfusate proteomic profiles, with the hypothesis that in-depth profiling may reveal biologically meaningful information on how donor kidneys benefit from this intervention. METHODS: Multiplexed liquid chromatography-tandem mass spectrometry was used to obtain a proteome profile of 210 perfusate samples. Partial least squares discriminant analysis and multivariate analysis involving clinical and perfusion parameters were used to identify associations between profiles and clinical outcomes. RESULTS: Identification and quantitation of 1716 proteins indicated that proteins released during perfusion originate from the kidney tissue and blood, with blood-based proteins being the majority. Data show that the overall hypothermic machine perfusion duration is associated with increasing levels of a subgroup of proteins. Notably, high-density lipoprotein and complement cascade proteins are associated with 12-month outcomes, and blood-derived proteins are enriched in the perfusate of kidneys that developed acute rejection. CONCLUSIONS: Perfusate profiling by mass spectrometry was informative and revealed proteomic changes that are biologically meaningful and, in part, explain the clinical observations of the COMPARE trial.


Assuntos
Transplante de Rim , Humanos , Transplante de Rim/métodos , Proteoma/metabolismo , Proteômica , Preservação de Órgãos/métodos , Rim/metabolismo , Perfusão/métodos , Doadores de Tecidos
5.
Diagnostics (Basel) ; 12(12)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36553167

RESUMO

The testing capacity of the laboratory is paramount for better control of the pandemic caused by SARS-CoV-2. The pooling method is promising to increase testing capacity, and the use of direct NAAT-based detection of SARS-CoV-2 on a non-invasive specimen such as saliva will ultimately accelerate the testing capacity. This study aims to validate the pooling-of-four method to quadruple the testing capacity using RNA-extraction-free saliva specimens. In addition, we intend to investigate the preferable stage of pooling, including pre- or post-heating. The compatibility of this approach was also tested on five commercial kits. Saliva specimens stored at -80 °C for several months were proven viable and were used for various tests in this study. Our findings revealed that pooling-of-four specimens had an overall agreement rate of 98.18% with their individual testing. Moreover, we proved that the pooling procedure could be conducted either pre- or post-heating, with no discordance and no significant difference in Ct values generated. When compared to other commercial detection kits, it demonstrated an overall agreement greater than 85%, which exhibits broad compatibility and ensures easy adaptability in clinical settings. This method has been proven reliable and increases the testing capacity up to fourfold.

6.
EClinicalMedicine ; 50: 101516, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35784435

RESUMO

Background: Donor-characteristics and donor characteristics-based decision algorithms are being progressively used in the decision process whether or not to accept an available donor kidney graft for transplantation. While this may improve outcomes, the performance characteristics of the algorithms remains moderate. To estimate the impact of donor factors of grafts accepted for transplantation on transplant outcomes, and to test whether implementation of donor-characteristics-based algorithms in clinical decision-making is justified, we applied an instrumental variable analysis to outcomes for kidney donor pairs transplanted in different individuals. Methods: This analysis used (dis)congruent outcomes of kidney donor pairs as an instrument and was based on national transplantation registry data for all donor kidney pairs transplanted in separate individuals in the Netherlands (1990-2018, 2,845 donor pairs), and the United Kingdom (UK, 2000-2018, 11,450 pairs). Incident early graft loss (EGL) was used as the primary discriminatory factor. It was reasoned that a scenario with a dominant impact of donor variables on transplantation outcomes would result in high concordance of EGL in both recipients, whilst dominance of asymmetrical outcomes could indicate a more complex scenario, involving an interaction of donor, procedural and recipient factors. Findings: Incidences of congruent EGL (Netherlands: 1·2%, UK: 0·7%) were slightly lower than the arithmetical (stochastic) incidences, suggesting that once a graft has been accepted for transplantation, donor factors minimally contribute to incident EGL. A long-term impact of donor factors was explored by comparing outcomes for functional grafts from donor pairs with asymmetrical vs. symmetrical outcomes. Recipient survival was similar for both groups, but a slightly compromised graft survival was observed for grafts with asymmetrical outcomes in the UK cohort: (10-years Hazard Ratio for graft loss: 1·18 [1·03-1·35] p<0·018); and 5 years eGFR (48·6 [48·3-49·0] vs. 46·0 [44·5-47·6] ml/min in the symmetrical outcome group, p<0·001). Interpretation: Our results suggest that donor factors for kidney grafts deemed acceptable for transplantation impact minimally on transplantation outcomes. A strong reliance on donor factors and/or donor-characteristics-based decision algorithms could result in unjustified rejection of grafts. Future efforts to optimize transplant outcomes should focus on a better understanding of the recipient factors underlying transplant outcomes. Funding: None.

7.
J Clin Med ; 11(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35456312

RESUMO

BACKGROUND: In kidney transplantation, the relative contribution of various donor, procedure and recipient-related factors on clinical outcomes is unknown. Previous paired studies have largely focused on examining factors predicting early outcomes, where the effect of donor factors is thought to be most important. Here, we sought to examine the relationship between early and long-term outcomes in a UK-wide paired kidney analysis. METHODS: UK Transplant Registry data covering 24,090 kidney transplants performed between 2001-2018, where both kidneys from each donor were transplanted, were analysed. Case-control studies were constructed using matched pairs of kidneys from the same donor discordant for outcome, to delineate the impact of transplant and recipient factors on longer-term outcomes. RESULTS: Multivariable conditional logistic regression identified HLA mismatch as an important predictor of prolonged delayed graft function (DGF), in the context of a paired study controlling for the influence of donor factors, even when adjusting for early acute rejection. Prolonged DGF, but not human leucocyte antigen (HLA) mismatch, strongly predicted 12-month graft function, and impaired 12-month graft function was associated with an increased risk of graft failure. CONCLUSIONS: This study indicates prolonged DGF is associated with adverse long-term outcomes and suggests that alloimmunity may contribute to prolonged DGF by a mechanism distinct from typical early acute rejection.

8.
Am J Transplant ; 22(4): 1073-1087, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34878723

RESUMO

In brain death, cerebral injury contributes to systemic biological dysregulation, causing significant cellular stress in donor kidneys adversely impacting the quality of grafts. Here, we hypothesized that donation after brain death (DBD) kidneys undergo proteolytic processes that may deem grafts susceptible to posttransplant dysfunction. Using mass spectrometry and immunoblotting, we mapped degradation profiles of cytoskeletal proteins in deceased and living donor kidney biopsies. We found that key cytoskeletal proteins in DBD kidneys were proteolytically cleaved, generating peptide fragments, predominantly in grafts with suboptimal posttransplant function. Interestingly, α-actinin-4 and talin-1 proteolytic fragments were detected in brain death but not in circulatory death or living donor kidneys with similar donor characteristics. As talin-1 is a specific proteolytic target of calpain-1, we investigated a potential trigger of calpain activation and talin-1 degradation using human ex vivo precision-cut kidney slices and in vitro podocytes. Notably, we showed that activation of calpain-1 by transforming growth factor-ß generated proteolytic fragments of talin-1 that matched the degradation fragments detected in DBD preimplantation kidneys, also causing dysregulation of the actin cytoskeleton in human podocytes; events that were reversed by calpain-1 inhibition. Our data provide initial evidence that brain death donor kidneys are more susceptible to cytoskeletal protein degradation. Correlation to posttransplant outcomes may be established by future studies.


Assuntos
Transplante de Rim , Obtenção de Tecidos e Órgãos , Morte Encefálica/patologia , Proteínas do Citoesqueleto , Sobrevivência de Enxerto , Humanos , Rim/patologia , Transplante de Rim/efeitos adversos , Transplante de Rim/métodos , Doadores Vivos , Proteólise , Doadores de Tecidos
9.
Front Cell Infect Microbiol ; 11: 691538, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485174

RESUMO

Saliva as a sample matrix has been an attractive alternative for the detection of SARS-CoV-2. However, due to potential variability in collection and processing steps, evaluating a proposed workflow amongst the local population is recommended. Here, we aim to validate the collection and treatment of human saliva as a direct specimen for RT-qPCR-based detection of SARS-CoV-2 in Indonesia. We demonstrated that SARS-CoV-2 target genes were detected in saliva specimens and remained stable for five days either refrigerated or stored at room temperature. The method of processing saliva specimens described in this report bypasses the need for an RNA-extraction process, thereby reducing the cost, time, and manpower required for processing samples. The developed method was tested across nine commercial kits, including the benchmark, to demonstrate its wide applicability on multiple existing workflows. Our developed method achieved an 86% overall agreement rate compared to paired nasopharyngeal and oropharyngeal swab specimens (NPOP). With the assistance of a saliva sampling device, the collection was found to be more convenient for individuals and improved the overall agreement rate to 97%.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Indonésia , Nasofaringe , RNA Viral/genética , Saliva , Manejo de Espécimes
10.
Front Genet ; 10: 1028, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781154

RESUMO

Background: Soil-transmitted helminths have been shown to have the immune regulatory capacity, which they use to enhance their long term survival within their host. As these parasites reside in the gastrointestinal tract, they might modulate the immune system through altering the gut bacterial composition. Although the relationships between helminth infections or the microbiome with the immune system have been studied separately, their combined interactions are largely unknown. In this study we aim to analyze the relationship between bacterial communities with cytokine response in the presence or absence of helminth infections. Results: For 66 subjects from a randomized placebo-controlled trial, stool and blood samples were available at both baseline and 21 months after starting three-monthly albendazole treatment. The stool samples were used to identify the helminth infection status and fecal microbiota composition, while whole blood samples were cultured to obtain cytokine responses to innate and adaptive stimuli. When subjects were free of helminth infection (helminth-negative), increasing proportions of Bacteroidetes was associated with lower levels of IL-10 response to LPS {estimate [95% confidence interval (CI)] -1.96 (-3.05, -0.87)}. This association was significantly diminished when subjects were helminth-infected (helminth positive) (p-value for the difference between helminth-negative versus helminth-positive was 0.002). Higher diversity was associated with greater IFN-γ responses to PHA in helminth-negative (0.95 (0.15, 1.75); versus helminth-positive [-0.07 (-0.88, 0.73), p-value = 0.056] subjects. Albendazole treatment showed no direct effect in the association between bacterial proportion and cytokine responses, although the Bacteroidetes' effect on IL-10 responses to LPS tended downward in the albendazole-treated group [-1.74 (-4.08, 0.59)] versus placebo [-0.11 (-0.84, 0.62); p-value = 0.193]. Conclusion: We observed differences in the relationship between gut microbiome composition and immune responses, when comparing individuals infected or uninfected with geohelminths. Although these findings are part of a preliminary exploration, the data support the hypothesis that intestinal helminths may modulate immune responses, in unison with the gut microbiota. Trial Registration: ISRCTN, ISRCTN83830814. Registered 27 February 2008 - Retrospectively registered, http://www.isrctn.com/ISRCTN83830814.

11.
Transplantation ; 103(2): 323-328, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30157158

RESUMO

BACKGROUND: Cerebral injury during donation after brain death may induce systemic damage affecting long-term kidney function posttransplantation. Conventional evaluation of donor organ quality as a triage for transplantation is of limited utility. METHODS: We compared donor kidneys yielding opposing extremes of the continuum of posttransplantation outcomes by several common kidney biopsy evaluation techniques, including Kidney Donor Profile Index and Remuzzi scoring, and analyzed tissue from a minimal sample cohort using label-free quantitation mass spectrometry. Further assessment of the proteomic results was performed by orthogonal quantitative comparisons of selected key proteins by immunoblotting. RESULTS: We show that common evaluation techniques of kidney biopsies were not predictive for posttransplantation outcomes. In contrast, despite the limited cohort size, the proteomic analysis was able to clearly differentiate between kidneys yielding extreme posttransplantation outcome differences. Pathway analysis of the proteomic data suggested that outcome-related variance in protein abundance associated with profibrotic, apoptosis, and antioxidant proteins. Immunoblotting confirmation further supported this observation. CONCLUSIONS: We present preliminary data indicating that there is scope for existing evaluation approaches to be supplemented by the analysis of proteomic differences. Furthermore, the observed outcome-related variance in a limited cohort was supported by immunoblotting and is consistent with mechanisms previously implicated in the development of injury and cytoprotection in kidney transplantation.


Assuntos
Transplante de Rim , Rim/fisiopatologia , Proteômica , Doadores de Tecidos , Adulto , Idoso , Aloenxertos , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Anal Chim Acta ; 1037: 107-118, 2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30292284

RESUMO

Schistosoma mansoni is a parasitic helminth that infects millions of people mostly in tropical parts of the world. Different life cycle stages of S.mansoni, that infect or develop in the human host, promote distinct immune responses and are known for their ability to modulate host immune responses. However, the molecular mechanisms through which the parasites interact with, and modulate the host immune system remain incompletely understood. Despite the well-known ability of various lipids to modulate immune responses, a comprehensive analysis of the lipidome of the different life cycle stages has not been performed. Using three complementary MS-based platforms to detect and quantify around 350 lipid species, we here characterized the lipid profiles of S. mansoni cercariae, worms and eggs, as well as extracts and excretory/secretory (ES) products of different life cycle stages of S. mansoni. We identified life cycle stage specific signatures of lipid classes of which cercariae were found to have the most distinct profile. Moreover, we detected several immunolomodulatory oxylipids in the different life cycle stages. Specifically, prostaglandins were found to be most highly enriched in egg preparations, while resolvins were specifically detected in cercariae. Together, the generation of this detailed lipid database of the different life cycle stages of S. mansoni will not only be important for a better understanding of the biology of the parasite itself but also of host-parasite interactions and how that could result in immunomodulation.


Assuntos
Lipídeos/imunologia , Schistosoma mansoni/imunologia , Animais , Interações Hospedeiro-Parasita , Humanos , Imunomodulação
13.
Sci Rep ; 8(1): 8539, 2018 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-29867102

RESUMO

Ischaemia and reperfusion injury (IRI) is the leading cause of acute kidney injury (AKI), which contributes to high morbidity and mortality rates in a wide range of injuries as well as the development of chronic kidney disease. The cellular and molecular responses of the kidney to IRI are complex and not fully understood. Here, we used an integrated proteomic and metabolomic approach to investigate the effects of IRI on protein abundance and metabolite levels. Rat kidneys were subjected to 45 min of warm ischaemia followed by 4 h and 24 h reperfusion, with contralateral and separate healthy kidneys serving as controls. Kidney tissue proteomics after IRI revealed elevated proteins belonging to the acute phase response, coagulation and complement pathways, and fatty acid (FA) signalling. Metabolic changes were already evident after 4 h reperfusion and showed increased level of glycolysis, lipids and FAs, whilst mitochondrial function and ATP production was impaired after 24 h. This deficit was partially compensated for by the contralateral kidney. Such a metabolic balance counteracts for the developing energy deficit due to reduced mitochondrial function in the injured kidney.


Assuntos
Nefropatias/metabolismo , Rim/metabolismo , Metabolômica , Proteômica , Traumatismo por Reperfusão/metabolismo , Animais , Ácidos Graxos/metabolismo , Glicólise , Rim/patologia , Nefropatias/patologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteoma/metabolismo , Ratos , Ratos Endogâmicos F344 , Traumatismo por Reperfusão/patologia , Transdução de Sinais
14.
PLoS Biol ; 16(4): e2005504, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29668708

RESUMO

The molecular mechanisms through which dendritic cells (DCs) prime T helper 2 (Th2) responses, including those elicited by parasitic helminths, remain incompletely understood. Here, we report that soluble egg antigen (SEA) from Schistosoma mansoni, which is well known to drive potent Th2 responses, triggers DCs to produce prostaglandin E2 (PGE2), which subsequently-in an autocrine manner-induces OX40 ligand (OX40L) expression to license these DCs to drive Th2 responses. Mechanistically, SEA was found to promote PGE2 synthesis through Dectin-1 and Dectin-2, and via a downstream signaling cascade involving spleen tyrosine kinase (Syk), extracellular signal-regulated kinase (ERK), cytosolic phospholipase A2 (cPLA2), and cyclooxygenase 1 and 2 (COX-1 and COX-2). In addition, this pathway was activated independently of the actions of omega-1 (ω-1), a previously described Th2-priming glycoprotein present in SEA. These findings were supported by in vivo murine data showing that ω-1-independent Th2 priming by SEA was mediated by Dectin-2 and Syk signaling in DCs. Finally, we found that Dectin-2-/-, and to a lesser extent Dectin-1-/- mice, displayed impaired Th2 responses and reduced egg-driven granuloma formation following S. mansoni infection, highlighting the physiological importance of this pathway in Th2 polarization during a helminth infection. In summary, we identified a novel pathway in DCs involving Dectin-1/2-Syk-PGE2-OX40L through which Th2 immune responses are induced.


Assuntos
Células Dendríticas/imunologia , Dinoprostona/imunologia , Lectinas Tipo C/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Células Th2/imunologia , Animais , Antígenos de Helmintos/imunologia , Antígenos de Helmintos/farmacologia , Comunicação Autócrina , Diferenciação Celular , Ciclo-Oxigenase 1/genética , Ciclo-Oxigenase 1/imunologia , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/parasitologia , Dinoprostona/metabolismo , Enterotoxinas/farmacologia , Regulação da Expressão Gênica , Humanos , Lectinas Tipo C/deficiência , Lectinas Tipo C/genética , Sistema de Sinalização das MAP Quinases , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante OX40 , Fosfolipases A2/genética , Fosfolipases A2/imunologia , Cultura Primária de Células , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Esquistossomose mansoni/genética , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/patologia , Quinase Syk/genética , Quinase Syk/imunologia , Células Th2/efeitos dos fármacos , Células Th2/parasitologia , Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/imunologia
15.
Ecol Lett ; 21(4): 536-545, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29417715

RESUMO

Ecological theory suggests that co-infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) between malaria and bloodsucking helminths can regulate malaria population dynamics, but the importance of RBC competition in human hosts was unknown. We analysed infection density (i.e. the concentration of parasites in infected hosts), from a 2-year deworming study of over 4000 human subjects. After accounting for resource-use differences among parasites, we find evidence of resource competition, priority effects and a competitive hierarchy within co-infected individuals. For example reducing competition via deworming increased Plasmodium vivax densities 2.8-fold, and this effect is limited to bloodsucking hookworms. Our ecological, resource-based perspective sheds new light into decades of conflicting outcomes of malaria-helminth co-infection studies with significant health and transmission consequences. Beyond blood, investigating within-human resource competition may bring new insights for improving human health.


Assuntos
Coinfecção , Helmintíase , Malária , Parasitos , Animais , Ecologia , Helmintíase/complicações , Helmintos , Humanos , Malária/complicações , Camundongos
16.
Front Immunol ; 8: 1429, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163504

RESUMO

Recently, it has become clear that short-chain fatty acids (SCFAs), and in particular butyrate, have anti-inflammatory properties. Murine studies have shown that butyrate can promote regulatory T cells via the induction of tolerogenic dendritic cells (DCs). However, the effects of SCFAs on human DCs and how they affect their capacity to prime and polarize T-cell responses have not been addressed. Here, we report that butyrate suppresses LPS-induced maturation and metabolic reprogramming of human monocyte-derived DCs (moDCs) and conditions them to polarize naive CD4+ T cells toward IL-10-producing type 1 regulatory T cells (Tr1). This effect was dependent on induction of the retinoic acid-producing enzyme retinaldehyde dehydrogenase 1 in DCs. The induction of retinaldehyde dehydrogenase activity and Tr1 cell differentiation by butyrate was dependent on simultaneous inhibition of histone deacetylases and signaling through G protein-coupled receptor 109A. Taken together, we reveal that butyrate is a potent inducer of tolerogenic human DCs, thereby shedding new light on the cellular and molecular mechanisms through which SCFAs can exert their immunomodulatory effects in humans.

17.
Int Arch Allergy Immunol ; 174(3-4): 170-182, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29130972

RESUMO

BACKGROUND: Dendritic cells (DCs) are the sentinels of the immune system. Upon recognition of a pathogen, they mature and migrate to draining lymph nodes to prime and polarize T cell responses. Although it is known that helminths and helminth-derived molecules condition DCs to polarize T helper (Th) cells towards Th2, the underlying mechanisms remain incompletely understood. OBJECTIVES: The aim of this study was to conduct a proteome analysis of helminth antigen-stimulated DCs in order to gain more insight into the cellular processes associated with their ability to polarize immune responses. METHODS: We analyzed the maturation and polarization of monocyte-derived DCs from 9 donors at 2 different time points after stimulation with different Th1- and Th2-polarizing pathogen-derived molecules. The samples were measured using liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry for relative quantitation. RESULTS: Lipopolysaccharide-induced maturation promoted the expression of proteins related to metabolic, cellular, and immune system processes. Th1-polarizing DCs, conditioned by IFN-γ during maturation, displayed accelerated maturation by differentially expressing cytoskeletal proteins and proteins involved in immune regulation. The stimulation of DCs with soluble egg antigens and omega-1 derived from Schistosoma mansoni, which are both Th2-inducing stimuli, increased 60S acidic ribosomal protein P2, and vesicle amine transferase 1 while decreasing the expression of proteins related to antigen processing and presentation. CONCLUSION: Our data indicate that not only proteins involved in the interaction between T cells and DCs at the level of the immunological synapse, but also those related to cellular metabolism and stress, may promote Th2 polarization.


Assuntos
Células Dendríticas/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Células Th1/imunologia , Células Th2/imunologia , Animais , Apresentação de Antígeno , Antígenos de Helmintos/imunologia , Diferenciação Celular , Células Cultivadas , Proteínas do Ovo/imunologia , Humanos , Evasão da Resposta Imune , Interferon gama/imunologia , Lipopolissacarídeos/imunologia , Proteômica
18.
Parasitology ; 144(7): 965-974, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28290266

RESUMO

For the majority of intestinal parasites, real-time PCR-based diagnosis outperforms microscopy. However, the data for Trichuris trichiura have been less convincing and most comparative studies have been performed in populations with low prevalence. This study aims to improve detection of T. trichuria DNA in human stool by evaluating four sample preparation methods. Faecal samples (n = 60) were collected at Flores island, Indonesia and examined by microscopy. Aliquots were taken and a bead-beating procedure was used both on directly frozen stool and on material preserved with 96% ethanol. PCR on frozen samples showed 40% to be positive for T. trichiura, compared with 45% positive by microscopy. The percentage positive increased when using ethanol preservation (45·0%), bead-beating (51·7%) and a combination (55·0%) and all three methods showed significantly higher DNA loads. The various procedures had a less pronounced effect on the PCR results of nine other parasite targets tested. Most prevalent were Ascaris lumbricoides (≈60%), Necator americanus (≈60%), Dientamoeba fragilis (≈50%) and Giardia lamblia (≈12%). To validate the practicality of the procedure, bead-beating was applied in a population-based survey testing 910 stool samples. Findings confirmed bead-beating before DNA extraction to be a highly efficient procedure for the detection of T. trichiura DNA in stool.


Assuntos
Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase em Tempo Real , Manejo de Espécimes , Tricuríase/diagnóstico , Trichuris/isolamento & purificação , Adulto , Animais , Pré-Escolar , Etanol/química , Fezes/parasitologia , Feminino , Humanos , Indonésia/epidemiologia , Lactente , Microscopia , Pessoa de Meia-Idade , Prevalência , Tricuríase/epidemiologia , Tricuríase/parasitologia , Adulto Jovem
19.
Malar J ; 16(1): 50, 2017 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-28129772

RESUMO

BACKGROUND: Concern exists about the safety of iron supplementation given to individuals in malarious areas. The possible unfavourable impact of iron supplementation on malaria might be less when slow-release iron compounds are used instead of ferrous salts, because no toxic non-transferrin bound iron is formed. The aim of this study was to determine the effect of iron supplementation using the slow-release iron compound iron polymaltose (IPM) on the acquisition of malarial parasitaemia. METHODS: A randomized, placebo-controlled trial was performed in schoolchildren aged 5-18 years with mild or moderate anaemia on the Indonesian island Flores. Microscopic malaria-negative children were randomized to receive 8 weeks of IPM (6 mg elemental iron/kg/day) or placebo . The primary outcomes were the occurrence of microscopically detectable malarial parasitaemia at week 4, 8, 12 and 16 after start of treatment and the proportion of participants with real-time (RT) PCR positive malarial parasitaemia at week 16. RESULTS: 294 Children were assigned to the IPM group and 297 to the placebo group. Whereas IPM supplementation failed to increased haemoglobin or ferritin concentrations, the IPM group had a significantly higher rate of occurrence of microscopically detectable parasitaemia [hazard ratio 2.2, 95% C.I. 1.2-4.0; P = 0.01]. This higher rate was confined to iron-replete children. At the end of the study, 89% of the children in the IPM group had remained free from microscopically detectable parasitaemia vs 95% of children in the placebo group. The proportion of plasmodial RT-PCR positive children was similar in both groups at week 16 (IPM group 16.6% vs placebo group 14.3%; P = 0.47). When analysis was restricted to iron-replete children (serum ferritin ≥30 µg/l), there was a trend for a higher proportion being RT-PCR positive at week 16 in the IPM group compared with the placebo group (20 vs 13.3%; P = 0.07). Erythrocyte microcytosis was an independent risk factor for microscopically detectable malarial parasitaemia. CONCLUSIONS: A short course of IPM should be used cautiously in anaemic children in malaria endemic areas, as it has limited efficacy in treating iron deficiency, while it increases the rate of microscopic malarial parasitaemia in those with replete iron stores. Trial registration ISRCTN 83091970. Registered 16 May 2012 (retrospectively registered).


Assuntos
Compostos Férricos/administração & dosagem , Malária/complicações , Parasitemia/prevenção & controle , Adolescente , Anemia/sangue , Criança , Pré-Escolar , Suplementos Nutricionais/análise , Índices de Eritrócitos , Feminino , Hemoglobinas/análise , Humanos , Incidência , Indonésia/epidemiologia , Malária/sangue , Malária/epidemiologia , Masculino , Parasitemia/sangue , Parasitemia/epidemiologia , Parasitemia/parasitologia , Risco
20.
Proc Natl Acad Sci U S A ; 113(44): 12526-12531, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27791067

RESUMO

In cross-sectional studies, chronic helminth infections have been associated with immunological hyporesponsiveness that can affect responses to unrelated antigens. To study the immunological effects of deworming, we conducted a cluster-randomized, double-blind, placebo-controlled trial in Indonesia and assigned 954 households to receive albendazole or placebo once every 3 mo for 2 y. Helminth-specific and nonspecific whole-blood cytokine responses were assessed in 1,059 subjects of all ages, whereas phenotyping of regulatory molecules was undertaken in 121 school-aged children. All measurements were performed before and at 9 and 21 mo after initiation of treatment. Anthelmintic treatment resulted in significant increases in proinflammatory cytokine responses to Plasmodium falciparum-infected red blood cells (PfRBCs) and mitogen, with the largest effect on TNF responses to PfRBCs at 9 mo-estimate [95% confidence interval], 0.37 [0.21-0.53], P value over time (Ptime) < 0.0001. Although the frequency of regulatory T cells did not change after treatment, there was a significant decline in the expression of the inhibitory molecule cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) on CD4+ T cells of albendazole-treated individuals, -0.060 [-0.107 to -0.013] and -0.057 [-0.105 to -0.008] at 9 and 21 mo, respectively; Ptime = 0.017. This trial shows the capacity of helminths to up-regulate inhibitory molecules and to suppress proinflammatory immune responses in humans. This could help to explain the inferior immunological responses to vaccines and lower prevalence of inflammatory diseases in low- compared with high-income countries.


Assuntos
Albendazol/uso terapêutico , Infecções Comunitárias Adquiridas/prevenção & controle , Helmintíase/tratamento farmacológico , Helmintos/efeitos dos fármacos , Adolescente , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Criança , Infecções Comunitárias Adquiridas/imunologia , Infecções Comunitárias Adquiridas/parasitologia , Estudos Transversais , Citocinas/sangue , Citocinas/imunologia , Método Duplo-Cego , Feminino , Helmintíase/epidemiologia , Helmintíase/imunologia , Helmintos/imunologia , Interações Hospedeiro-Parasita/efeitos dos fármacos , Interações Hospedeiro-Parasita/imunologia , Humanos , Indonésia/epidemiologia , Masculino , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/imunologia , Prevalência , Resultado do Tratamento , Adulto Jovem
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